Optimax
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From: wakefield
that could explain it, my local garage is extremly busy as it sits right next to the M1 & gets loads of local stuff as well.
As I say, never had a problem with it, in fact if anything it makes my scoob a bit toooo fast
shunty
As I say, never had a problem with it, in fact if anything it makes my scoob a bit toooo fast
shunty
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From: London
over 6k miles, roughly 1/2 on SUL and 1/2 on Optimax, the average mpg I've got on optimax is 18.82, on SUL it's 20.11. Not a massive difference but I would have thought big enough to be significant. The car is STi 7 (MY02) so should have a 'quicker learning' ECU. The price of optimax is always 79/80p/l whereas SUL seems to vary from 76-84p 
. In short, i am not convinced that optimax is 'better' than good quality SUL, but I run a few tanks of it now and then in the hope of washing away deposits from SUL, and visa versa. Could be this is a complete waste of time but hey, it's all petrol in the end... 
. In short, i am not convinced that optimax is 'better' than good quality SUL, but I run a few tanks of it now and then in the hope of washing away deposits from SUL, and visa versa. Could be this is a complete waste of time but hey, it's all petrol in the end...
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Nom
The reason Optimax is lower duty is because of its low sulphur content, not its octane rating (which is high) and no, it is the base distilate which is higher octane (this is not achieved with additives)
Ho hum...busy at work...
The reason Optimax is lower duty is because of its low sulphur content, not its octane rating (which is high) and no, it is the base distilate which is higher octane (this is not achieved with additives)
Ho hum...busy at work...
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Oh, OK, Jules! That is good to know. I've been using the Customs & Excise way it's noted (95RON + additives) as an 'excuse' () for why it's round that way, but have doubtless been talking out of things that weren't designed for talking I'm not very up on the ins & outs of this stuff...
But it does seem to be more variable than others, which is odd! Maybe all the 97 we use actually isn't 97 (more like 95), nor is the 95 what it says it is when the 97 isn't available... I don't trust any of these garages! Just go over to Europe & fill up with their SUL (98) or even the 99+ & you'll know what Optimax SHOULD be like all the time
) for why it's round that way, but have doubtless been talking out of things that weren't designed for talking I'm not very up on the ins & outs of this stuff...But it does seem to be more variable than others, which is odd! Maybe all the 97 we use actually isn't 97 (more like 95), nor is the 95 what it says it is when the 97 isn't available... I don't trust any of these garages! Just go over to Europe & fill up with their SUL (98) or even the 99+ & you'll know what Optimax SHOULD be like all the time
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From: the fastest rentals in town......0-100mph in 10 seconds
How many times is this topic going to be discussed, wouldn't it be easier to use search and spend the next three weeks reading the old threads
My 2pth but I've used Optimax since it came out with no bad effects that I can see. That's on a MY94 UK car with Unichip so perhaps that's why.
Would a car running a standard ECU benefit, surely you'd need a compensated map to take any real benefit...
My 2pth but I've used Optimax since it came out with no bad effects that I can see. That's on a MY94 UK car with Unichip so perhaps that's why.
Would a car running a standard ECU benefit, surely you'd need a compensated map to take any real benefit...
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Just read through all the stuff above about "....I always use 1 in 4 Optimax.....blah....blah...blah" and everyone has forgotten the question about Formula Shell.....I remember it well (I'm now in my early 30's)...I'd just started driving and had a 1275cc Marina....those were the days!!! Anyway Formula Shell was well hyped....it had a "spark enhancing additive" which promised enhanced burning, smoothness, reduced emisions, increased MPG etc etc. Some of the claims were justified (but with the Marina I probably could have run it on prune juice and not noticed the difference...it was SO gutless), but some cars, notably GM's had problems with the lubrication of the valve guides/seats not being lubed properly. Of course it was taken of the market pretty sharpish and it's been 15 years since Shell have been bold enough to try it again.
James
James
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I've tried many combinations with fuel and have found that SUL and optimax on my 94 import seem the same.
The best result I have had so far is running optimax with Octane Boost. This gave the car a much smoother ride - THE WAY IT SHOULD RUN! This also seemed to remove the flat spot at around 2000 RPM, just before the turbo starts to spin up.
Obviously, the jap impreza is designed to run on 100 RON fuel (i think), therefore the optimax (98) with the boost (2) should equal about 100 RON
The best result I have had so far is running optimax with Octane Boost. This gave the car a much smoother ride - THE WAY IT SHOULD RUN! This also seemed to remove the flat spot at around 2000 RPM, just before the turbo starts to spin up.
Obviously, the jap impreza is designed to run on 100 RON fuel (i think), therefore the optimax (98) with the boost (2) should equal about 100 RON
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From: Cheshire
Cant say too much, but i know someone who works in the labs' at Shell Oil refinery.
The 'opinion' that i got was "if you feel optimax makes your car run better - use it". The company do claim that Optimax 'does' clean your engine, but as for the long term affects stated earlier in this thread ..i cant comment.
Ive got an MY93 wrx, and in my case i reckon im getting 330km with Optimax as to 300km with NUL.(on full tank) I also feel that my car runs better. I tend to use the stuff as often as i can, but do have to switch to NUL when i cant get it.
So, as my contact says, its pretty much a matter of choice ...
The 'opinion' that i got was "if you feel optimax makes your car run better - use it". The company do claim that Optimax 'does' clean your engine, but as for the long term affects stated earlier in this thread ..i cant comment.
Ive got an MY93 wrx, and in my case i reckon im getting 330km with Optimax as to 300km with NUL.(on full tank) I also feel that my car runs better. I tend to use the stuff as often as i can, but do have to switch to NUL when i cant get it.
So, as my contact says, its pretty much a matter of choice ...
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stephenuk300
does optimax octane rating degrade over time? answer-NO
is optimax STD UNLEADED with octane booster? answer-NO
is it bad for your uk300? answer-ID SAY NO
some of these claims that so called 'my friends sisters brothers dad is a lab technician and has tested it and its trash' are just claims, no proof is in it or it would be published
if you have any more questions about it i run your local optimax outlet (we have spoken once before 99%sure), pop in and we can have a chat and if you still have concerns ill put you onto someone from shell uk who im sure would be happy to help.
regards
mike
[Edited by mbc - 11/1/2002 3:56:43 PM]
does optimax octane rating degrade over time? answer-NO
is optimax STD UNLEADED with octane booster? answer-NO
is it bad for your uk300? answer-ID SAY NO
some of these claims that so called 'my friends sisters brothers dad is a lab technician and has tested it and its trash' are just claims, no proof is in it or it would be published
if you have any more questions about it i run your local optimax outlet (we have spoken once before 99%sure), pop in and we can have a chat and if you still have concerns ill put you onto someone from shell uk who im sure would be happy to help.
regards
mike
[Edited by mbc - 11/1/2002 3:56:43 PM]
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From: Cheshire
My friend works for 'Shell Global Solutions' which is the research arm of Shell UK .... and yes they do the testing for Ferrari ...and no i dont know anything about that.
But i did ask about Optimax, cos like alot of people on here the question of Optimax was one i wanted answering ....didnt want to be wasting my money etc..
i was directed to take a look at the Shell Website, where there is a reasonable amount of info, but the individuals advice to me was 'if u like it, use it' ... suppose you cant be more fair and honest than that ... still doesnt help tho' ....there certainly doesnt appear to be any clear indication of mpg improvements, but i seem to get better than using NUL.
I am led to believe that Optimax is 98Ron, where SUL is 97 and NUL is 95.
I am tempted to try SUL, just to see how it goes ...
But i did ask about Optimax, cos like alot of people on here the question of Optimax was one i wanted answering ....didnt want to be wasting my money etc..
i was directed to take a look at the Shell Website, where there is a reasonable amount of info, but the individuals advice to me was 'if u like it, use it' ... suppose you cant be more fair and honest than that ... still doesnt help tho' ....there certainly doesnt appear to be any clear indication of mpg improvements, but i seem to get better than using NUL.
I am led to believe that Optimax is 98Ron, where SUL is 97 and NUL is 95.
I am tempted to try SUL, just to see how it goes ...
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From: Gosport, Hampshire
I use Optimax all the time and I notice a marked difference if I have to put an ordinary SUL in instead - my car is a MY94 WRX Jap, full decat, running 301bhp when using Optimax and Octane Boost (to get near what the car was designed to run on - 100 RON)
Even without the Octane Boost my car runs better on Optimax.
I have had the car on a Dyno with ordinary SUL and the BHP drops to 287.
Obviously different atmospheric pressures and other factors could have affected the readings as they were done on different days but the difference is noticable when you drive the car. Optimax seems to give a sharper pick up.
I would guess from all the posts here that it is very much a question of Optimax suiting some car setups and not others.
For me I just can't see past it!!!
Even without the Octane Boost my car runs better on Optimax.
I have had the car on a Dyno with ordinary SUL and the BHP drops to 287.
Obviously different atmospheric pressures and other factors could have affected the readings as they were done on different days but the difference is noticable when you drive the car. Optimax seems to give a sharper pick up.
I would guess from all the posts here that it is very much a question of Optimax suiting some car setups and not others.
For me I just can't see past it!!!
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From: Nr Bath, Wilts
I also emailed Shell, to get the party line Got the following reply this morning...
As said, it's the "Party Line" but it answers some of my questions anyway
Got the following reply this morning...
Simon,
Thank you for your recent email regarding Shell Optimax, the Scoobynet bulletin board was a very interesting read. I have now received the following information from our Automotive Fuels Manager.
'All Optimax is batch tested at Stanlow refinery and is manufactured to meet a minimum specification of 98 RON, typically batches have been measured at 98.5 RON.
Clearly, as with any precision test method, there is a repeatability margin on the test and when identical tests are carried out by different operators on different samples from different locations this margin is greatly increased (reproducibility).
Petrol is made up of many different components all of which will vary in octane quality. Some of the lighter components are high octane and therefore if the fuel is stored under sub standard conditions and the light ends are allowed to escape then the octane quality may deteriorate. This will not happen in normal use when the petrol is stored correctly.
Optimax is a uniquely formulated fuel which gains its high octane from refinery streams - it does not contain any octane boosting additives.
The detergent additives used in Shell Optimax are designed to dissolve the carbonaceous deposits on the inlet valves and wash them into the combustion chamber where they are burnt along with the fuel. These additives have been tested both in the lab and over many millions of miles in the field and have been found to cause no detrimental effects after prolonged use.'
I do hope that the above information will help to assure you of the high quality of Shell Optimax. If I can be of any further assistance please do not hesitate to contact me.
Yours sincerely
Customer Service Professional
Shell U.K. Oil Products Limited
Rowlandsway House, Rowlandsway, Manchester M22 5SB, United Kingdom
Thank you for your recent email regarding Shell Optimax, the Scoobynet bulletin board was a very interesting read. I have now received the following information from our Automotive Fuels Manager.
'All Optimax is batch tested at Stanlow refinery and is manufactured to meet a minimum specification of 98 RON, typically batches have been measured at 98.5 RON.
Clearly, as with any precision test method, there is a repeatability margin on the test and when identical tests are carried out by different operators on different samples from different locations this margin is greatly increased (reproducibility).
Petrol is made up of many different components all of which will vary in octane quality. Some of the lighter components are high octane and therefore if the fuel is stored under sub standard conditions and the light ends are allowed to escape then the octane quality may deteriorate. This will not happen in normal use when the petrol is stored correctly.
Optimax is a uniquely formulated fuel which gains its high octane from refinery streams - it does not contain any octane boosting additives.
The detergent additives used in Shell Optimax are designed to dissolve the carbonaceous deposits on the inlet valves and wash them into the combustion chamber where they are burnt along with the fuel. These additives have been tested both in the lab and over many millions of miles in the field and have been found to cause no detrimental effects after prolonged use.'
I do hope that the above information will help to assure you of the high quality of Shell Optimax. If I can be of any further assistance please do not hesitate to contact me.
Yours sincerely
Customer Service Professional
Shell U.K. Oil Products Limited
Rowlandsway House, Rowlandsway, Manchester M22 5SB, United Kingdom
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MBC,
Are you the one around Leighton Buzzard sometimes as well?
I have run OPTIMAX since I bought the car a year ago (7500 miles)and have not had any problems. This has just come about when I had the first years service done, and the recommendation from Subaru was not to use it all the time. When you spend £25k on a new car, the last thing you want to do is do anything to it that could damage the car. We rely on these people to advise us on what is right for our cars. I did put a tank of SUL in once and found the car was very groggy. I'm currently trying SUL again over a month or so to see if I notice any difference. If you don't notice any difference, what is the point of OPTIMAX???
Are you the one around Leighton Buzzard sometimes as well?
I have run OPTIMAX since I bought the car a year ago (7500 miles)and have not had any problems. This has just come about when I had the first years service done, and the recommendation from Subaru was not to use it all the time. When you spend £25k on a new car, the last thing you want to do is do anything to it that could damage the car. We rely on these people to advise us on what is right for our cars. I did put a tank of SUL in once and found the car was very groggy. I'm currently trying SUL again over a month or so to see if I notice any difference. If you don't notice any difference, what is the point of OPTIMAX???
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stevenuk300,
Possibly you may notice a difference under certain conditions like steep gradients - maybe not. But one point in buying it (especially if you don't notice a difference) is the cost. It can be several pence per litre cheaper than SUL.
Every couple of weeks I switch between the two - perhaps that'll half any possible problems?
Possibly you may notice a difference under certain conditions like steep gradients - maybe not. But one point in buying it (especially if you don't notice a difference) is the cost. It can be several pence per litre cheaper than SUL.
Every couple of weeks I switch between the two - perhaps that'll half any possible problems?
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steven
yes i live in leighton,seen ya a couple of times around both towns.
weather the differance is noticeable i think maybe down to different cars and as said above somewhere different set ups, i found something rather strange when i put in super, that the car seems to respond fine for first 1/2 tank then seems to go a bit groggy like you mentioned although not on a scale that worrys me at all, then i put optimax back in and its back to normal.
i wouldnt normally comment as i did above but i felt that most of the, may i say 'bullsh*t' claims made are simply that 'bullsh*t' until publicly proven otherwise, then ill eat humble pie lol. at the end of the day its your car and your investment id say stick with super if subaru say so, but i really think that they should enlighten us 'ALL' into why this is.
regards and see ya around
mike
yes i live in leighton,seen ya a couple of times around both towns.
weather the differance is noticeable i think maybe down to different cars and as said above somewhere different set ups, i found something rather strange when i put in super, that the car seems to respond fine for first 1/2 tank then seems to go a bit groggy like you mentioned although not on a scale that worrys me at all, then i put optimax back in and its back to normal.
i wouldnt normally comment as i did above but i felt that most of the, may i say 'bullsh*t' claims made are simply that 'bullsh*t' until publicly proven otherwise, then ill eat humble pie lol
. at the end of the day its your car and your investment id say stick with super if subaru say so, but i really think that they should enlighten us 'ALL' into why this is.regards and see ya around
mike
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From: Gosport, Hampshire
Having posted earlier that my car runs better on Optimax and Octane Booster than anything else - maybe its because my car (Jap Spec) was designed to run on 100RON fuel. Is it possible that UK spec cars do not take so well to this as their ECU's are not programmed to use such high octane fuel?
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It's funny how so many people have different opinions on fuel. Some prefer Optimax, others SUL, some say don't mix fuels, and others recommend mixing SUL and Optimax. Talk about confusing.
It seems it's all down to preference. If your car runs fine on the fuel your using, then stick with it. I'll still continue my own test with SUL, and if I don't notice a difference change back to Optimax. Like the chicken and Egg question, there seems no correct answer to this.
Thanks for the advice guys.
See you around
Steven
It seems it's all down to preference. If your car runs fine on the fuel your using, then stick with it. I'll still continue my own test with SUL, and if I don't notice a difference change back to Optimax. Like the chicken and Egg question, there seems no correct answer to this.
Thanks for the advice guys.
See you around
Steven
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There's another thread at the moment where Optimax was (very allegedly) giving rise to detonation. My engine went bang so sticking with SUL, which (another point of view!) it is consistently good on. I wonder if the model year affects this - mines a 99
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I think its one of those sticky topics again. IF your car runs well on Optimax DONT STOP USING IT. IF it doesnt, dont slag it off. I have been using Optimax since the car came into the country. Since running the car on Optimax & NF im getting absolutely NO KNOCK CORRECTION. I wont stop using it BUT i cant comment on SUL as i havent yet used it.
Cheers
Gez
Cheers
Gez
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I use optimax non-stop in my MY94 Legacy Turbo. Seems great. Almost no difference between Optimax and SUL at first, but longer term there is a definite imrovement in throttle response, and (bizarre as this may seem) the engine started to sound a bit different. More 'purrrrry' if that makes sense.
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From: Lancashire
Just to say my 93WRX runs very happily on Optimax but try NUL+ booster and the performance is dire so I only use it in emergencies.
Shell do a good web site telling you where garages are so route planning is possible.
SUL is O.K. but I prefer to stick to what I like !
My mechanical friend says it is important on imports to use the highest octane rating you can buy but warns against booster as part of the permanent diet - but its fine for track days/occasional use.
Shell do a good web site telling you where garages are so route planning is possible.
SUL is O.K. but I prefer to stick to what I like !
My mechanical friend says it is important on imports to use the highest octane rating you can buy but warns against booster as part of the permanent diet - but its fine for track days/occasional use.
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stevenuk300
if some subaru dealers are saying there can be a problem with optimax,will they put it in writing then we can take away some of the fog from this discussion.
a)shell are clearly saying its ok (well they would wouldn't they but then they have done lots of testing and invested loads of money)however subarus are unusual and they may have overlooked something. (possibly, we dont know)
b) if some dealers are seeing problems is it in all models? If not which ones and why aren't they telling us all.I have just had mine serviced and the guy there did not know of problems related to optimax but then he wasnt a mechanic.
c) how do we contact IM to get the offical subaru position?
nav
if some subaru dealers are saying there can be a problem with optimax,will they put it in writing then we can take away some of the fog from this discussion.
a)shell are clearly saying its ok (well they would wouldn't they but then they have done lots of testing and invested loads of money)however subarus are unusual and they may have overlooked something. (possibly, we dont know)
b) if some dealers are seeing problems is it in all models? If not which ones and why aren't they telling us all.I have just had mine serviced and the guy there did not know of problems related to optimax but then he wasnt a mechanic.
c) how do we contact IM to get the offical subaru position?
nav
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